The present invention relates to a diamond wire saw used for cutting stones, glass, silicon, etc., and more particularly to such a diamond wire saw in which the diamond abrasive layer of each diamond abrasive barrel has two halves spirally arranged in parallel at different elevations, and the lower half of the diamond abrasive layer works when the higher half of the diamond abrasive layer starts to wear.
A regular diamond wire saw is generally comprised of a steel cable and a plurality of diamond abrasive barrels mounted around the steel cable and connected in series. The diamond abrasive barrels each have a diamond abrasive layer covered on the outside wall thereof for cutting (see FIG. 1). The diamond abrasive layer has diamond grains arranged on it. Because each diamond abrasive barrel has a smooth outside wall with a diamond abrasive layer of substantially uniform thickness covered thereon, it wears quickly at one side. Furthermore, the linear cutting operation of conventional diamond wire saws achieves low cutting efficiency.